Multiple-purpose vehicle

ABSTRACT

A gear transmission ( 20 ) includes a plurality of shift gears ( 36, 37 ), a plurality of shifters ( 55, 56 ) engaged, respectively, with the plurality of shift gears ( 36, 37 ), and a shift drum ( 58 ) rotatably operated by a stepped speed changing operational tool ( 66 ) to operate the plurality of shifters ( 55, 56 ), thus being speed-changed in forward three speed stages. The stepped speed changing operational tool ( 66 ) is switched to a neutral position, a forward third speed position, a forward second speed position and a forward first speed position in this cited order.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.17/319,537, filed May 13, 2021, which claims priority to Japanese PatentApplication No. 2020-168722 filed Oct. 5, 2020, the disclosure of whichis hereby incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a multiple-purpose vehicle.

2. Description of Related Art

A known multiple-purpose vehicle includes a stepless speed changingdevice and a gear transmission provided in series in a travelingtransmission system for transmitting power from an engine to a travelingdevice and configured to speed-change the power from the engine andtransmit the resultant power to the traveling device. The known vehiclefurther includes a stepless speed changing operational tool forspeed-changing operation of the stepless speed changing device and astepped speed changing operational tool for speed-changing operation ofthe gear transmission, the stepless speed changing operational tool andthe stepped speed changing operational tool being provided separately.

In this type of multiple-purpose vehicle, the gear transmission includesa plurality of shift gears, a plurality of shifters engaged respectivelywith the plurality of shift gears, a shift drum having, it is outercircumference portion, a plurality of shifter operational cam portionsto which the plurality of shifters are engaged respectively and operablycoupled to the stepped speed changing operational tool, the geartransmission being configured such that the shift gears areengaged/disengaged with/from speed changing gears for setting speeds asthe plurality of shifters are operated by the shifter operational camportions.

An example of a multiple-purpose vehicle of this type is known from e.g.Patent Document 1. The multiple-purpose vehicle disclosed in PatentDocument 1 includes a hydrostatic stepless speed changing device as astepless speed changing device speed-changed by a speed changing pedalas the stepless speed changing operational tool and includes also atransmission speed-changed by a speed changing lever as the steppedspeed changing operational tool. The transmission includes a firstshifter and a second shifter as “shift gears”, a first shift fork as a“shifter” engaged with the first shifter and a second shift fork as a“shifter” engaged with the second shifter, and a cam shaft as a “shiftdrum” having in its outer circumference portion a first guide groove asa “shifter operational cam portion” engageable with the first shift forkand a second guide groove as a “shifter operational cam portion”engageable with the second shift fork.

-   Patent Document 1: Japanese Unexamined Patent Application No.    2009-67082 document.

SUMMARY OF THE INVENTION

In this type of multiple-purpose vehicle, main speed changing operationsof the traveling speed are effected by the stepless speed changingdevice and auxiliary speed changing operations of the traveling speedare effected by the gear transmission. If the number of speeds forutility works that can be provided by the auxiliary speed changingoperations is small, the number of kinds of utility work that can becarried out with using the multiple-purpose vehicle is limiteddisadvantageously. Thus, there is a need for ability to provide aplurality of speed stages by auxiliary speed changing operations forutility works.

The present invention provides a multiple-purpose vehicle that canprovide a plurality of speed stages by auxiliary speed changingoperations for utility works and that also can be used conveniently.

A multiple-purpose vehicle according to one embodiment of the presentinvention comprises:

a stepless speed changing device and a gear transmission provided inseries in a traveling transmission system for transmitting power from anengine to a traveling device and configured to speed-change the powerfrom the engine and transmit the resultant power to the travelingdevice;

a stepless speed changing operational tool for speed-changing operationof the stepless speed changing device; and

a stepped speed changing operational tool provided separately of thestepless speed changing operational tool and provided for speed-changingoperation of the gear transmission;

wherein the gear transmission includes a plurality of shift gears, aplurality of shifters engaged respectively with the plurality of shiftgears, a shift drum having, it is outer circumference portion, aplurality of shifter operational cam portions to which the plurality ofshifters are engaged respectively and operably coupled to the steppedspeed changing operational tool;

wherein the gear transmission is configured such that the shift gearsare engaged/disengaged with/from speed changing gears for setting speedsas the plurality of shifters are operated by the shifter operational camportions in association with a rotational operation of the shift drum bythe stepped speed changing operational tool and further configured tospeed-change power inputted thereto to forward traveling power inforward three speed stages; and wherein the stepped speed changingoperational tool is configured to be capable of switching to a neutralposition, a forward third speed position corresponding to a forwardthird speed, a forward second speed position corresponding to a forwardsecond speed lower than the forward third speed and a forward firstspeed position corresponding to a forward first speed lower than theforward second speed in this cited order.

With the above-described inventive arrangement, the gear transmissioncan be speed-changed in forward three speed stages, so even if speedstage for realizing forward third speed is set for moving (traveling),it is still possible to set (assign) the two speed stages of the forwardfirst speed and the forward second speed for a utility work, thus,auxiliary speed changing operations for a utility work can be effectedin two speed stages.

With a multiple-purpose vehicle, traveling thereof effected by auxiliaryspeed changing operation to a high speed is effected more frequentlythan traveling with auxiliary speed changing to a low speed. For thisreason, the stepped speed changing operational tool is switched from theneutral position to the forward third speed more frequently than beingswitched from the neutral position to the forward first speed or to theforward second speed. Therefore, it is convenient that switchover to theforward third speed position can be effected more speedily thanswitchover to the forward first speed position or to the forward secondspeed position from the neutral position.

In the present invention, preferably:

the speed changing gears include a third speed gear for setting theforward third speed, a second speed gear having an outside diametergreater than an outside diameter of the third speed gear for setting theforward second speed, and a first speed gear having an outside diametergreater than the outside diameter of the second speed gear for settingthe forward first speed;

the third speed gear, the second speed gear and the first speed gear aresupported to a rotation support shaft extending in a lateral widthdirection of the gear transmission; and

the first speed gear is supported to the rotation support shaft betweenthe second speed gear and the third speed gear.

In general, an intra-case space at the center portion of thetransmission case lateral width direction can be formed large moreeasily than an intra-case space in the transmission case lateral sideportion. In the above arrangement, since the first speed gear having anoutside diameter greater than the outside diameters of the third speedgear and the second speed gear is disposed at the center portion of theintra-case space that can be readily formed large, the first speed gear,the second speed gear and the third speed gear can be readily assembledinside the transmission case.

Further, preferably, in the lateral width direction of the geartransmission, the first speed gear is disposed on more inner side of themachine body than the second speed gear and more inner side of themachine body than the third speed gear.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a left side view showing a multiple-purpose vehicle in itsentirety,

FIG. 2 is a plan view showing a traveling power transmission system,

FIG. 3 is an explanatory view showing operational positions of a steppedspeed changing operational tool,

FIG. 4 is a left side view showing a gear transmission,

FIG. 5 is a plan view showing the gear transmission,

FIG. 6 is a diagram showing the gear transmission,

FIG. 7 is a section view showing a speed changing section of the geartransmission,

FIG. 8 is a side view showing a coupling mechanism, and

FIG. 9 is a side view showing a detent mechanism.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Next, an embodiment as an example of the present invention will beexplained with reference to the accompanying drawings.

Incidentally, in the following explanation, with respect to a travelingvehicle body of a multiple-purpose vehicle, the direction of arrow Fshown in FIG. 1 is defined as “vehicle body front side”, the directionof arrow B shown therein is defined as “vehicle body rear side”, thedirection of arrow U shown therein is defined as “vehicle body upperside”, the direction of arrow D shown therein is defined as “vehiclebody lower side”, the direction on the near (front) side of the plane ofillustration is defined as “vehicle body left side”, and the directionon the far (back) side of the plane of illustration is defined as“vehicle body right side”, respectively.

[General Arrangement of Multiple-Purpose Vehicle]

As shown in FIG. 1 , the multiple-purpose vehicle includes a travelingvehicle body having a pair of steerable and drivable left and rightfront wheels 1 as “traveling devices” and a pair of drivable left andright rear wheels 2 as further “traveling devices”. At a front/rearintermediate portion of the traveling vehicle body, a riding section 3is formed. In this riding section 3, there are provided a driver's seat4, a driving section 3A including a steering wheel 5 for steering thefront wheels 1, and a rear seat 6 disposed on more rear side than thedriver's seat 4. At a rear portion of the traveling vehicle body, aload-carrying deck 7 is provided. Beneath the load-carrying deck 7,there is provided an engine 8 outputting power to the front wheels 1 andthe rear wheels 2.

[Traveling Power Transmission System]

FIG. 2 is a plan view showing a traveling power transmission systemconfigured to transmit power from the engine 8 to the front wheels 1(see FIG. 1 ) and the rear wheels 2 (see FIG. 1 ). This traveling powertransmission system includes a stepless speed changing device 10 and agear transmission 20 configured to speed-change power from the engine 8and to output the resultant power to the front wheels 1 and the rearwheels 2. The gear transmission 20 is provided rearwardly of the engine8. The stepless speed changing device 10 and the gear transmission 20are arranged in series with each other so that the output of thestepless speed changing device 10 is inputted to the gear transmission20. In this embodiment, power of an output shaft 8 a of the engine 8 isinputted to the stepless speed changing device 10 and the powerspeed-changed by the stepless speed changing device 10 is inputted tothe gear transmission 20 and the power speed-changed by the geartransmission 20 is outputted from a front wheel output shaft 51 whichprotrudes forwardly from a lower portion of a transmission case 21 tothe front wheels 1. The power speed-changed by the gear transmission 20is transmitted from a rear wheel differential mechanism 53 providedwithin a rear portion of the transmission case 21 to the rear wheels 2via left and right rear wheel driving shafts 53 b. The front wheeloutput shaft 51 is coupled to a front wheel differential mechanism (notshown) provided inside a front wheel driving case 9 (see FIG. 1 ) via arotational shaft 51 a (see FIG. 1 ).

[Stepless Speed Changing Device]

As shown in FIG. 2 , the stepless speed changing device 10 is providedbetween a lateral side of the engine 8 and a lateral side of the geartransmission 20. This stepless speed changing device 10 includes a speedchanging case 11. Inside this speed changing case 11, there are providedan input pulley 12 operably coupled to the output shaft 8 a of theengine 8, an output pulley 13 operably coupled to an input shaft (firstshaft 23) of the gear transmission 20, and an endless rotation belt 14wound around the input pulley 12 and the output pulley 13. The inputpulley 12 and the output pulley 13 are constituted of split pulleys toallow changing of a winding diameter of the endless rotation belt 14.The stepless speed changing device 10 is constituted as a so-called belttype stepless speed changing device.

As shown in FIG. 2 , an accelerator pedal 16 coupled via an acceleratorcoupling mechanism 15 to an accelerator device 8 b of the engine 8 and aspeed changing operation section 10 a provided in the stepless speedchanging device 10 are coupled to each other via a stepless speedchanging coupling mechanism 17. The accelerator pedal 16 is provided inthe driving section 3A. When the accelerator device 8 b is operated bythe accelerator pedal 16 to adjust the engine rotation speed to therising side, due to the action of the stepless speed changing couplingmechanism 17, the speed changing operation section 10 a is operated inoperative association with the action of the accelerator device 8 b, thestepless speed changing device 10 is speed-changed toward the high speedside. When the accelerator device 8 b is operated by the acceleratorpedal 16 to adjust the engine rotation speed to the falling side, due tothe action of the stepless speed changing coupling mechanism 17, thespeed changing operation section 10 a is operated in operativeassociation with the action of the accelerator device 8 b, the steplessspeed changing device 10 is speed-changed toward the low speed side.

The stepless speed changing device 10 is configured to be speed-changedas a main speed changing device for changing driving speeds of the frontwheels 1 and the rear wheels 2. Speed changing operations of thestepless speed changing device 10 are effected by the accelerator pedal16 acting as a “stepless speed changing operational tool”. Specifically,when the accelerator pedal 16 is operated, the belt winding diameters ofthe input pulley 12 and the output pulley 13 are changed, and the powerinputted from the engine 8 to the input pulley 12 is speed-changedsteplessly between the input pulley 12 and the output pulley 13 andoutputted as such from the output pulley 13 to the gear transmission 20.

[Gear Transmission]

The gear transmission 20, as shown in FIG. 2 , includes the transmissioncase 21 and is arranged in such a manner that the lateral widthdirection of the transmission case 21 is aligned with the lateral widthdirection of the traveling vehicle body. As shown in FIG. 4 , FIG. 5 andFIG. 6 , the gear transmission 20 includes a speed changing section 20Ahaving a first shaft 23 rotatably supported to a front upper portion ofthe transmission case 21, etc. and a transmission mechanism 20Bconfigured to output power of the speed changing section 20A to thefront wheels 1 and the rear wheels 2.

The speed changing section 20A, as shown in FIGS. 5 and 6 , includes, inaddition to the first shaft 23, a second shaft 24 and a third shaft 25which are provided inside the transmission case 21 and arranged side byside in parallel with the first shaft 23. The first shaft 23, the secondshaft 24 and the third shaft 25 are provided to extend along the lateralwidth direction of the transmission case 21.

One end side of the first shaft 23 protrudes from the transmission case21 toward the stepless speed changing device 10 and is coupled to theoutput pulley 13 of the stepless speed changing device 10. The firstshaft 23 acts as an input shaft of the gear transmission 20. As shown inFIGS. 5 and 6 , inside the transmission case 21, the first shaft 23mounts thereon a first input gear 26, a second input gear 27, a thirdinput gear 28, and a fourth input gear 29.

As shown in FIGS. 5 and 6 , a second shaft 24, as a “rotation supportshaft”, rotatably mounts thereon a first speed (speed changing) gear 31meshed with the first input gear 26 for setting a forward first speed, asecond speed (speed changing) gear 32 meshed with the second input gear27 for setting a forward second speed, and a third speed (speedchanging) gear 33 meshed with the third input gear 28 for setting aforward third speed. A reverse-rotation gear 34 meshed with the fourthinput gear 29 is mounted on a third shaft 25, and a reverse travelinggear 35 meshed with the reverse-rotation gear 34 for setting reversefirst speed is rotatably mounted on the second shaft 24.

As shown in FIG. 7 , the outside diameter of the first speed gear 31 isset larger than the outside diameter of the third speed gear 33. Theoutside diameter of the first speed gear 31 is set also larger than theoutside diameter of the second speed gear 32. The outside diameter ofthe second speed gear 32 is set larger than the outside diameter of thethird speed gear 33. The first speed gear 31 whose outside diameter islarger than the outside diameter of the second speed gear 32 and theoutside diameter of the third speed gear 33 is located on more innerside than the second speed gear 32 and located also on more inner sidethan the third speed gear 33, in the lateral width direction of thetransmission case 21.

As shown in FIG. 7 , between the first speed gear 31 and the third speedgear 33, a first shift gear 36 is supported to the second shaft 24. Thefirst shift gear 36 is supported on the second shaft 24 to be slidableto a transmission state in which the first shift gear 36 is meshed witha teeth portion 31 a formed at a lateral portion of the first speed gear31 to operably couple the first speed gear 31 to the second shaft 24, atransmission state in which the first shift gear 36 is meshed with ateeth portion 33 a formed at a lateral portion of the third speed gear33 to operably couple the third speed gear 33 to the second shaft 24,and a neutral state in which the first shift gear 36 is removed from theteeth portion 31 a of the first speed gear 31 to release the operablecoupling of the first speed gear 31 relative to the second shaft 24 andalso removed from the teeth portion 33 a of the third speed gear 33 torelease the operable coupling of the third speed gear 33 relative to thesecond shaft 24.

As shown in FIG. 7 , between the second speed gear 32 and the reversetraveling gear 35, a second shift gear 37 is supported to the secondshaft 24. The second shift gear 37 is supported on the second shaft 24to be slidable to a transmission state in which the second shift gear 37is meshed with a teeth portion 32 a formed at a lateral portion of thesecond speed gear 32 to operably couple the second speed gear 32 to thesecond shaft 24, a transmission state in which the second shift gear 37is meshed with a teeth portion 35 a formed at a lateral portion of thereverse traveling gear 35 to operably couple the reverse traveling gear35 to the second shaft 24, and a neutral state in which the second shiftgear 37 is removed from the teeth portion 32 a of the second speed gear32 to release the operable coupling of the second speed gear 32 relativeto the second shaft 24 and also removed from the teeth portion 35 a ofthe reverse traveling gear 35 to release the operable coupling of thereverse traveling gear 35 relative to the second shaft 24.

As shown in FIG. 6 , the transmission mechanism 20B includes a fifthshaft 49 as a “rotation transmission shaft” having one end portionthereof operably coupled to the second shaft 24 via a gear couplingmechanism 40 having a fourth shaft 41, etc., a front wheel output shaft51 operably coupled to the other end of the fifth shaft 49 via a bevelgear mechanism 50 for outputting power of the fifth shaft 49 to thefront wheel 1, and a rear wheel differential mechanism 53 having aninput gear 53 a thereof operably coupled to an intermediate portion ofthe fifth shaft 49 for outputting power of the fifth shaft 49 to therear wheel 2. The input gear 53 a is engaged with a transmission gear 52provided on the fifth shaft 49, thus being operably coupled to thisfifth shaft 49. The front wheel output shaft 51 is provided to extend inthe front/rear direction of the transmission case 21. The fourth shaft41 and the fifth shaft 49 are provided to extend along the lateral widthdirection of the transmission case 21.

The gear coupling mechanism 40, as shown in FIG. 6 , includes, inaddition to the fourth shaft 41, a first transmission gear 42 mounted onthe second shaft 24, a second transmission gear 43 mounted at one endportion of the fourth shaft 41 and meshed with the first transmissiongear 42, a third transmission gear 44 provided at the other end portionof the fourth shaft 41, and a fourth transmission gear 45 meshed withthe third transmission gear 44 and provided at one end portion of thefifth shaft 49.

As shown in FIG. 7 , at an angular portion opposed to the firsttransmission gear 42 at the root portion of the reverse traveling gear35, there is formed a stepped portion 35 b for mitigating stressconcentration. At an angular portion opposed to the first transmissiongear 42 at the root portion of the first speed gear 31, there is formeda stepped portion similar to the stepped portion 35 b of the reversetraveling gear 35.

As shown in FIGS. 5 and 7 , a first shifter 55 having a leading endportion 55 a thereof engaged with the first shift gear 36 and a secondshifter 56 having a leading end portion 56 a thereof engaged with thesecond shift gear 37 are slidably supported on a shifter support shaft57. This shifter support shaft 57 is supported to the transmission case21 in parallel juxtaposition with the second shaft 24. A shift drum 58having a drum axis Y parallel with a support axis X of the shift supportshaft 57 is rotatably supported to the transmission case 21. In theouter circumferential portion of the shift drum 58, there are provided afirst shifter operating cam portion 59 to which an operation portion 55b of the first shifter 55 is engaged and a second shifter operating camportion 60 to which an operation portion 56 b of the second shifter 56is engaged. The first shifter operating cam portion 59 and the secondshifter operating cam portion 60 are constituted of guide grooves intowhich the operation portions 55 b, 56 b respectively come into slidableengagement. As the shift drum 58 is rotated about the drum axis Y, thefirst shifter 55 is slid along the shifter support shaft 57 by the firstshifter operating cam portion 59 to slide the first shift gear 36 andthe second shifter 56 is slid along the shifter support shaft 57 by thesecond shifter operating cam portion 60 to slide the second shift gear37.

There is provided a speed changing operation shaft 61 for rotating theshift drum 58. Specifically, the speed changing operation shaft 61, asshown in FIGS. 5 and 7 , extends along the lateral width direction ofthe transmission case 21 and is rotatably supported to an upper portionof the transmission case 21 in parallel juxtaposition with the drum axisY. As shown in FIG. 7 , inside the transmission case 21, between one endportion of the speed changing operation shaft 61 and a supporting shaftportion 58 a of the shift drum 58, there is provided a couplingmechanism 62 for operably coupling the speed changing operation shaft 61with the shift drum 58. When the speed changing operation shaft 61 isrotatably operated, power of the speed changing operation shaft 61 istransmitted by the coupling mechanism 62 to the supporting shaft portion58 a, whereby the shift drum 58 is rotatably operated.

The coupling mechanism 62, as shown in FIGS. 7 and 8 , includes a drumoperating gear 63 provided on the support shaft portion 58 a of theshift drum 58 and rotatable with the shift drum 58 and a transmissiongear 64 provided at one end portion of the speed changing operationshaft 61 as being meshed with the drum operating gear 63 and rotatablewith the speed changing operation shaft 61. The transmission gear 64 isconstituted of a fan-shaped gear.

As shown in FIGS. 2 and 7 , a stepped speed changing operational tool 66is coupled via the coupling mechanism 65 to the speed changing operationshaft 61. The stepped speed changing operational tool 66 is provided atthe driving section 3A. The coupling mechanism 65 includes a pivot arm67 extended from the end portion of the speed changing operation shaft61 opposite to the side where the coupling mechanism 66 is provided, anoperation cable for coupling the pivot arm 67 to the stepped speedchanging operational tool 66, etc.

[Detent Mechanism]

A detent mechanism 70 is provided for fixing the shift drum 58 at arotation operation position where the first shift gear 36 and the secondshift gear 37 are engaged with each other or under the neutral state.The detent mechanism 70 is provided inside the transmission case 21.

Specifically, the detent mechanism 70, as shown in FIGS. 7 and 9 ,includes a positioning rotation portion 71 formed at the support shaftportion 58 a of the shift drum 58, a positioning arm 72 extended fromthe speed changing operation shaft 61 toward the positioning rotationportion 71 and a positioning spring 73 having a coil portion 73 athereof engaged on a boss portion 72 a of the positioning arm 72.

At five positions in the circumference portion of the positioningrotation portion 71, there are provided receded portions 74 as“positioning action portions”. The positioning arm 72 is rotatablysupported, at a boss portion 72 a provided at the base portion thereof,on the speed changing operation shaft 61. At the free end portion of thepositioning arm 72, a roller 75 is rotatably provided. In operation, asthe positioning arm 72 is pivoted about the speed changing operationshaft 61 in association with rotation of the positioning rotation shaft71, the positioning arm 72 will be engaged/disengaged with/from thereceded portion 74 by the roller 75 and with this engagement in thereceded portion 74, the positioning rotation portion 71 is fixed in arotational position corresponding to the rotation operation position ofthe shift drum 58. One end portion of the positioning spring 73 isretained to the positioning arm 72 and the other end portion of thepositioning spring 73 is retained to the transmission case 21. Thepositioning arm 72 is pivotally urged by the positioning spring 73 to beengaged in the receded portion 74.

[Rotation Potentiometer]

A rotation potentiometer 76 is provided for detecting an operationposition (operated position) of the speed changing operation shaft 61.This rotation potentiometer 76, as shown in FIGS. 4 and 7 , is providedoutside the transmission case 21. A meter case 76 a of the rotationpotentiometer 76 is screw-fixed to the transmission case 21. A rotationoperation shaft 76 b of the rotation potentiometer 76 is disposed suchthat the axis of this rotation operation shaft 76 b is positioned on theaxis of the speed changing operation shaft 61. The rotation operationshaft 76 b and the speed changing operation shaft 61 are engaged witheach other to be rotatable in unison. More particularly, the rotationoperation shaft 76 b and the speed changing operation shaft 61 areengaged with each other to be rotatable in unison, with engagement ofthe rotation operation shaft 76 b in a coupling hole provided in thespeed changing operation shaft 61. The engagement between the rotationoperation shaft 76 b and the speed changing operation shaft 61 isrealized by the rotation operation shaft 76 b and a non-circular shapeof the coupling hole.

The gear transmission 20 is configured to be speed-changed as anauxiliary speed changing device which changes the driving speeds of thefront wheels 1 and the rear wheels 2 in a reverse traveling one speed,and forward traveling three speeds, in total four speeds. Speed changingoperations of the gear transmission 20 are effected by the stepped speedchanging operational tool 66.

More particularly, as shown in FIG. 3 , the stepped speed changingoperational tool 66, in association with pivotal operations thereof, isguided by an operational tool guide 77 to be switched over to a neutralposition [N], a reverse (reverse traveling) position [R], a forwardfirst speed position [UL], a forward second speed position [L] and aforward third speed position [H].

The forward second speed position [L] is an operation position of alower speed than the forward third speed position [H]. The forward firstspeed position [UL] is an operation position of a lower speed than theforward second speed position [L]. Switching operations of the steppedspeed changing operation tool 66 to the neutral position [N], theforward third speed position [H], the forward second speed position [L]and the forward first speed position [UL] are effected in this mentionedorder. Namely, the stepped speed changing operation tool 66 is switchedfrom the neutral position [N] to the forward third speed position [H],switched from the forward third speed position [H] to the forward secondspeed position [L] and switched from the forward second speed position[L] to the forward first speed position [UL].

When the stepped speed changing operation tool 66 is operated to theneutral position [N], the speed changing operation shaft 61 is rotatedby the operation force of the stepped speed changing operation tool 66and in response to the operation force of the speed changing operationshaft 61, the shift drum 58 is rotated to a rotation operation positionfor realizing the neutral state. Then, the first shifter 55 is slid bythe first shifter operating cam portion 59, whereby the first shift gear36 is operated by the first shifter 55 to a state disengaged from thefirst speed gear 31 and from the third speed gear 33. Further, thesecond shifter 56 is slid by the second shifter operating cam portion60, whereby the second shift gear 37 is operated by the second shifter56 to a state disengaged from the second speed gear 32 and the reversetraveling gear 35. As the positioning rotation portion 71 is rotated inunison with the shift drum 58, the positioning arm 72 is engaged in afirst receded portion 74 a of the receded portions 74 provided at thefive positions and the shift drum 58 is position-fixed by the detentmechanism 70 at the rotation operation position providing the neutralstate (the rotation operation position where the first shift gear 36 andthe second shift gear 37 are disengaged). In the gear transmission 20,the neutral state is provided, whereby transmission of power of thefirst shaft 23 to the second shaft 24 is stopped and the output to thefront wheels 1 and the rear wheels 2 is stopped. The gear transmission20 is maintained under the neural state by the detent mechanism 70. Therotation operation shaft 76 b of the rotation potentiometer 76 isrotatably operated by the speed changing operation shaft 61 and theoperation position of the speed changing operation shaft 61 is detectedby the rotation potentiometer 76, and the detection result is outputtedas detection result of the neutral state of the gear transmission 20from the rotation potentiometer 76 to a display device (not shown) orthe like.

When the stepped speed changing operation tool 66 is operated to thereverse position [R], by the operation force of the speed changingoperation shaft 61, the shift drum 58 is operated to the rotationoperation position realizing reverse traveling. Then, the first shifter55 is slid by the first shifter operating cam portion 59 and the firstshift gear 36 is operated by the first shifter 55 to a state disengagedfrom the first speed gear 31 and the third speed gear 33. Further, thesecond shifter 56 is slid by the second shifter operating cam portion60, and the second shift gear 37 is operated by the second shifter 56into a state engaged with the reverse traveling gear 35. The positioningrotation portion 71 is rotated in unison with the shift drum 58 and thepositioning arm 72 is engaged with a second receded portion 74 b of thereceded portions 74 provided at the five positions and the shift drum 58is maintained by the detect mechanism 70 at the rotation operationposition realizing reverse traveling (the rotation operation position atwhich the second shift gear 37 is engaged with the reverse travelinggear 35 and the first shift gear 36 is disengaged from the first speedgear 31 and the third speed gear 33). In the gear transmission 20,reverse traveling state is provided, whereby the power of the firstshaft 23 is speed-changed into reverse traveling power by a fourth inputgear 29, a reverse-rotation gear 34 and a reverse traveling gear 35 andreverse traveling power is transmitted to the second shaft 24 andinputted from this second shaft 24 to the transmission mechanism 20B andreverse traveling power is outputted from the front wheel output shaft51 to the front wheels 1 and reverse traveling power is outputted fromthe reverse differential mechanism 53 to the rear wheels 2. The geartransmission 20 is maintained under the reverse traveling transmissionstate by the detent mechanism 70. The rotation operation shaft 76 b ofthe rotation potentiometer 76 is rotated by the speed changing operationshaft 61 and the operation position of the speed changing operationshaft 61 is detected by the rotation potentiometer 76 and the result ofthis detection is outputted from the rotation potentiometer 60 asdetection result of the reverse traveling transmission state of the geartransmission 20.

When the stepped speed changing operation tool 66 is operated to theforward third speed position [H], by the operation force of the steppedspeed changing operation tool 66, the speed changing operation shaft 61is rotated and by the operation force of this speed changing operationshaft 61, the shift drum 58 is rotatably operated to the rotationoperation position realizing forward third speed. Then, the firstshifter 55 is slid by the first shifter operating cam portion 59 and theshift gear 36 is operated by the first shifter 55 into a state engagedwith the third speed gear 33. Further, the second shifter 56 is slid bythe second shifter operating cam portion 60 and the second shift gear 37is operated by the second shifter 56 into a state disengaged from thesecond speed gear 32 and the reverse traveling gear 35. The positioningrotation portion 71 is rotated in unison with the shift drum 58 and thepositioning arm 72 is engaged in a third receded portion 74 c of thereceded portions 74 provided at the five positions, and the shift drum58 is fixed in position by the detent mechanism 70 at the rotationoperation position realizing the forward third speed (the rotationposition at which the first shift gear 36 is engaged with the thirdspeed gear 33 and the second shift gear 37 is disengaged from the secondspeed gear 32 and from the reverse traveling gear 35). In the geartransmission 20, there is provided a forward traveling transmissionstate of the forward traveling third speed, whereby the power of thefirst shaft 23 is speed-changed to the forward traveling third speedpower by the third input gear 28 and the third speed gear 33 and theforward traveling third speed power is transmitted to the second shaft24 and inputted from this second shaft 24 to the transmission mechanism20B and forward traveling third speed power of higher speed than theforward traveling first speed and the forward traveling second speed isoutputted from the front wheel output shaft 51 to the front wheels 1,and the forward traveling power of the forward traveling third speed isoutputted from the rear wheel differential mechanism 53 to the rearwheels 2. The gear transmission 20 is maintained under the forwardtraveling state of the forward third speed by the detent mechanism 70.The rotation operation shaft 76 b of the rotation potentiometer 76 isrotatably operated by the speed changing operation shaft 61 and theoperation position of the speed changing operation shaft 61 is detectedby the rotation potentiometer 76 and the result of this detection asdetection result of the forward traveling transmission state of theforward traveling third speed of the gear transmission 20 is outputtedfrom the rotation potentiometer 76.

When the stepped speed changing operation tool 66 is operated to theforward traveling second speed [L], by the operation force of thestepped speed changing operation tool 66, the speed changing operationshaft 61 is rotatably operated and by the operation force of the speedchanging operation shaft 61, the shift drum 58 is operated to therotation operation position realizing forward traveling second speed.Then, the first shifter 55 is slid by the first shifter operating camportion 59 and the first shift gear 36 is operated by the first shifter55 into a state disengaged from the first speed gear 31 and from thethird speed gear 33.

Further, the second shifter 56 is slid by the second shifter operatingcam portion 60 and the second shift gear 37 is operated by the secondshifter 56 into a state engaged with the second speed gear 32. Thepositioning rotation portion 71 is rotated in unison with the shift drum58 and the positioning arm 72 is engaged in a fourth receded portion 74d of the receded portions 74 provided at the five positions, and theshift drum 58 is fixed in position by the detent mechanism 70 at therotation operation position realizing the forward second speed (therotation position at which the first shift gear 36 is disengaged fromthe first speed gear 31 and from the third speed gear 33 and the secondshift gear 37 is engaged with the second speed gear 32). In the geartransmission 20, there is provided a forward traveling transmissionstate of the forward traveling second speed, whereby the power of thefirst shaft 23 is speed-changed to the forward traveling second speedpower by the second input gear 27 and the second speed gear 32 and theforward traveling second speed power is transmitted to the second shaft24 and inputted from this second shaft 24 to the transmission mechanism20B and forward traveling second speed power of lower speed than theforward traveling third speed and also higher speed than the forwardtraveling first speed is outputted from the front wheel output shaft 51to the front wheels 1, and the forward traveling power of the forwardtraveling second speed is outputted from the rear wheel differentialmechanism 53 to the rear wheels 2. The gear transmission 20 ismaintained under the forward traveling state of the forward second speedby the detent mechanism 70. The rotation operation shaft 76 b of therotation potentiometer 76 is rotatably operated by the speed changingoperation shaft 61 and the operation position of the speed changingoperation shaft 61 is detected by the rotation potentiometer 76 and theresult of this detection as detection result of the forward travelingtransmission state of the forward traveling second speed of the geartransmission 20 is outputted from the rotation potentiometer 76.

When the stepped speed changing operation tool 66 is operated to theforward traveling first speed [UL], by the operation force of thestepped speed changing operation tool 66, the speed changing operationshaft 61 is rotatably operated and by the operation force of the speedchanging operation shaft 61, the shift drum 58 is operated to therotation operation position realizing forward traveling first speed.Then, the first shifter 55 is slid by the first shifter operating camportion 59 and the first shift gear 36 is operated by the first shifter55 into a state engaged with the first speed gear 31. Further, thesecond shifter 56 is slid by the second shifter operating cam portion 60and the second shift gear 37 is operated by the second shifter 56 into astate disengaged from the second speed gear 32 and from the reversetraveling gear 35. The positioning rotation portion 71 is rotated inunison with the shift drum 58 and the positioning arm 72 is engaged in afifth receded portion 74 e of the receded portions 74 provided at thefive positions, and the shift drum 58 is fixed in position by the detentmechanism 70 at the rotation operation position realizing the forwardfirst speed (the rotation position at which the first shift gear 36 isengaged with the first speed gear 31 and the second shift gear 37 isdisengaged from the second speed gear 32 and from the reverse travelinggear 35). In the gear transmission 20, there is provided a forwardtraveling transmission state of the forward traveling first speed,whereby the power of the first shaft 23 is speed-changed to the forwardtraveling first speed power by the first input gear 26 and the firstspeed gear 31 and the forward traveling first speed power is transmittedto the second shaft 24 and inputted from this second shaft 24 to thetransmission mechanism 20B and forward traveling first speed power oflower speed than the forward traveling third speed and the forwardtraveling second speed is outputted from the front wheel output shaft 51to the front wheels 1, and the forward traveling power of the forwardtraveling first speed is outputted from the rear wheel differentialmechanism 53 to the rear wheels 2. The gear transmission 20 ismaintained under the forward traveling state of the forward first speedby the detent mechanism 70. The rotation operation shaft 76 b of therotation potentiometer 76 is rotatably operated by the speed changingoperation shaft 61 and the operation position of the speed changingoperation shaft 61 is detected by the rotation potentiometer 76 and theresult of this detection as detection result of the forward travelingtransmission state of the forward traveling first speed of the geartransmission 20 is outputted from the rotation potentiometer 76.

[Transmission Flexibility Portion]

As shown in FIG. 6 , the transmission mechanism 20B includes atransmission flexibility portion 80 configured to allow free rotation ofthe second shaft 24 as the “rotation support shaft” by a set rotationangle. More particularly, this transmission flexibility portion 80, asshown in FIG. 6 , is provided at a portion of the fifth shaft 49 as the“rotation transmission shaft” at which portion the gear couplingmechanism 40 is coupled. This portion of the fifth shaft 49 at whichportion the gear coupling mechanism 40 is coupled is a portion of thefifth shaft 49 on more transmission-wise upstream than the portions ofthe fifth shaft 49 at which portions the front wheel output shaft 51 andthe rear wheel differential mechanism 53 are coupled. The transmissionflexibility portion 80, as shown in FIG. 6 , includes a transmittingrotation portion 81 provided in the fourth transmission gear 45 androtatable with this fourth transmission gear 45 and a transmittedrotation portion 82 provided on the fifth shaft 49 and rotatabletogether with the fifth shaft 49. At a plurality of positions in thelateral portion of the transmitting rotation portion 81, transmittingprotrusions 83 are provided, whereas, at a plurality of positions in thelateral portion of the transmitted rotation portion 82, transmittedprotrusions 84 are provided. The transmitting protrusions 83 and thetransmitted protrusions 84 are provided in such a manner that onetransmitted protrusion 84 is engaged between mutually adjacenttransmitting protrusions 83 and also the transmitting protrusions 83 andthe transmitted protrusions 84 are position-displaceable by a setdisplacement angle A relative to each other.

With the transmission flexibility portion 80 in operation, as thetransmitting protrusion 83 and the transmitted protrusion 84 come intoabutment each other via respective end faces thereof, transmission offorward traveling power from the fourth transmission gear 45 to thefifth transmission shaft 49 is effected. When the transmittingprotrusion 83 and the transmitted protrusion 84 come into abutment eachother via respective other end faces thereof, transmission of reversetraveling power from the fourth transmission gear 45 to the fifth shaft49 is effected. And, by the relative positional displacement by the setdisplacement angle A between the transmitting protrusion 83 and thetransmitted protrusion 84, free rotation of the second shaft 24 by theset rotation angle A is allowed.

When the first shift gear 36 is to be engaged with the first speed gear31, even if respective end faces of the first shift gear 36 and theteeth portion 31 a of the first speed gear 31 hit each other, as freerotation of the second shaft 24 is allowed by the transmissionflexibility portion 80, the first shift gear 36 and the first speed gear31 can easily be displaced relative to each other in the rotationaldirection, so that the first shift gear 36 can come into engagement withthe teeth portion 31 a of the first speed gear 31 easily. This is alsotrue with the case of the first shift gear 36 being engaged with thethird speed gear 33, the case of the second shift gear 37 being engagedwith the second speed gear 32 and the case of the second shift gear 37being engaged with the reverse traveling gear 35.

In this embodiment, the transmitting protrusions 83 and the transmittedprotrusions 84 are provided. However, the transmission flexibilityportion may be alternatively configured such that a receded portion isprovided in one of the transmitting rotation portion 81 and thetransmitted rotation portion 82 and a transmitting protrusion which canslidably engage into the receded portion to be slidable by a setrotation angle is provided in the other of the transmitting rotationportion 81 and the transmitted rotation portion 82.

OTHER EMBODIMENTS

(1) In the foregoing embodiment, there was disclosed an example in whichthe stepless speed changing device 10 is constituted of a belt typestepless speed changing device. The invention is not limited thereto,but the stepless speed changing device 10 may be constituted of variouskinds of stepless speed changing device such as a hydrostatic steplessspeed changing device

(2) In the foregoing embodiment, there was disclosed an example in whichthe stepless speed changing device 10 and the gear transmission 20 areprovided in series in such a manner that power from the engine 8 isinputted to the stepless speed changing device 10 and output of thestepless speed changing device 10 is inputted to the gear transmission20. Alternatively, the stepless speed changing device 10 and the geartransmission 20 may be provided in series in such a manner that powerfrom the engine 8 is inputted to the gear transmission 20 and output ofthe gear transmission 20 is inputted to the stepless speed changingdevice 10.

(3) In the foregoing embodiment, there was disclosed an example in whichthe gear transmission 20 is configured to be capable of speed changingin reverse traveling one speed. Alternatively, it may be configured tobe capable of speed changing in two or more reverse traveling speeds.

In the foregoing embodiment, there was disclosed an example in which theaccelerator pedal 16 is provided as a stepless speed changingoperational tool. However, there may be provided a speed changing leverfor speed-changing the stepless speed changing device 10 only.

(4) In the foregoing embodiment, the front wheels 1 and the rear wheels2 are provided. Instead, crawler type traveling devices may be provided.

Industrial Applicability

The present invention is applicable to a multiple-purpose vehicleincluding a stepless speed changing device and a gear transmissionprovided in series in a traveling power transmission system fortransmitting power from an engine to a traveling device and configuredto speed-change the power from the engine and transmit the resultantpower to the traveling device, a stepless speed changing operationaltool for speed-changing operation of the stepless speed changing device,and a stepped speed changing operational tool for speed changing thegear transmission. The gear transmission is applicable to amultiple-purpose vehicle having a plurality of shift gears and a shiftdrum.

DESCRIPTION OF SIGNS

-   -   1: traveling device (front wheel)    -   2: traveling device (rear wheel)    -   8: engine    -   10: stepless speed changing device    -   16: stepless speed changing operational tool (accelerator pedal)    -   20: gear transmission    -   24: rotation support shaft (second shaft)    -   31: speed (changing) gear (first speed (changing) gear)    -   32: speed (changing) gear (second speed (changing) gear)    -   33: speed (changing) gear (third speed (changing) gear)    -   36: shift gear (first shift gear)    -   37: shift gear (second shift gear)    -   55: shifter (first shifter)    -   56: shifter (second shifter)    -   58: shift drum    -   59: shifter operational cam portion (first shifter operational        cam portion)    -   60: shifter operational cam portion (second shifter operational        cam portion)    -   66: stepped speed changing operational tool    -   H: forward third speed position    -   L: forward second speed position    -   UL: forward first speed position

The invention claimed is:
 1. A multiple-purpose vehicle including: agear transmission provided in series in a traveling transmission systemfor transmitting power from an engine to a traveling device having afront wheel and a rear wheel and configured to change power from theengine and transmit resultant power to the traveling device; and a speedchanging operational tool for speed-changing operation of the geartransmission, wherein the gear transmission comprises: a transmissioncase; a first shaft configured to receive power from the engine; a speedchanging operation shaft rotatable operably by an operation force of thespeed changing operational tool; a rotation transmission shaftconfigured to receive power from the first shaft the power being changedas the speed changing operation shaft is operably rotated; a front wheeloutput shaft configured to transmit power from the rotation transmissionshaft to the front wheel; and a rear wheel driving shaft configured totransmit power from the rotation transmission shaft to the rear wheel;wherein with a direction of a forward traveling of a vehicle body beingtaken as a front: the first shaft is disposed in an upper front portionof the transmission case, the speed changing operation shaft is disposedin an upper portion of the transmission case, the rotation transmissionshaft is disposed in a lower portion of the transmission case, the frontwheel output shaft is disposed in a lower front portion of thetransmission case, the rear wheel driving shaft is disposed in a rearportion of the transmission case, the front wheel output shaft projectsforward from the transmission case, and the first shaft, the speedchanging operation shaft, the rotation transmission shaft and the rearwheel driving shaft extend in a lateral width direction of the vehiclebody.
 2. The multiple-purpose vehicle according to claim 1, wherein: thespeed changing operation shaft is disposed rearward of the first shaft,the front wheel output shaft is disposed forward of the rotationtransmission shaft, and the rear wheel driving shaft is disposed belowthe first shaft and the speed changing operation shaft.
 3. Themultiple-purpose vehicle according to claim 1, wherein the speedchanging operation shaft is disposed between the rotation transmissionshaft and the rear wheel driving shaft as viewed from above.
 4. Themultiple-purpose vehicle according to claim 1, wherein the rear wheeldriving shaft is disposed rearward of the speed changing operation shaftand the rotation transmission shaft.
 5. The multiple-purpose vehicleaccording to claim 1, wherein the first shaft has a first input gear, asecond input gear, a third input gear and a fourth input gear, and thegear transmission further comprises: a second shaft extending in thelateral width direction of the vehicle body and disposed rearward of thefirst shaft; a plurality of speed gears disposed on the second shaft; athird shaft extending in the lateral width direction of the vehicle bodyforward of the first shaft; and a reverse-rotation gear disposed on thethird shaft and configured to mesh with the fourth input gear, andwherein, in response to the reverse-rotation gear meshed with the fourthinput gear, the first input gear, the second input gear, or the thirdinput gear being meshed with the corresponding speed gear, power fromthe engine is changed, respectively, as a rear first speed, a forwardfirst speed, a forward second speed, or a forward third speed, andtransmitted from the first shaft via the second shaft to the rotationtransmission shaft.
 6. The multiple-purpose vehicle according to claim5, wherein the speed gears include: a reverse traveling gear; a thirdspeed gear configured to set the forward third speed; a second speedgear having an outside diameter greater than an outside diameter of thethird speed gear, and configured to set the forward second speed; and afirst speed gear having an outside diameter greater than an outsidediameter of the second speed gear and configured to set the forwardfirst speed, wherein the first speed gear is supported to the secondshaft between the second speed gear and the third speed gear.
 7. Themultiple-purpose vehicle according to claim 6, wherein in the lateralwidth direction of the gear transmission, the first speed gear isdisposed inner of the second speed gear, and the first speed gear isdisposed inner of the third speed gear.